[PATCH 3/6] xfs: flag free space btree records that could be merged

Darrick J. Wong
2022-12-30T22:47:32Z

Complain if we encounter free space btree records that could be merged.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/scrub/alloc.c | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/scrub/alloc.c b/fs/xfs/scrub/alloc.c
index e9f8d29544aa..94f4b836c48d 100644
--- a/fs/xfs/scrub/alloc.c
+++ b/fs/xfs/scrub/alloc.c
@@ -31,6 +31,12 @@ xchk_setup_ag_allocbt(
}

/* Free space btree scrubber. */
+
+struct xchk_alloc {
+ /* Previous free space extent. */
+ struct xfs_alloc_rec_incore prev;
+};
+
/*
* Ensure there's a corresponding cntbt/bnobt record matching this
* bnobt/cntbt record, respectively.
@@ -93,6 +99,24 @@ xchk_allocbt_xref(
xchk_xref_is_not_cow_staging(sc, agbno, len);
}

+/* Flag failures for records that could be merged. */
+STATIC void
+xchk_allocbt_mergeable(
+ struct xchk_btree *bs,
+ struct xchk_alloc *ca,
+ const struct xfs_alloc_rec_incore *irec)
+{
+ if (bs->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ return;
+
+ if (ca->prev.ar_blockcount > 0 &&
+ ca->prev.ar_startblock + ca->prev.ar_blockcount == irec->ar_startblock &&
+ ca->prev.ar_blockcount + irec->ar_blockcount < (uint32_t)~0U)
+ xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+ memcpy(&ca->prev, irec, sizeof(*irec));
+}
+
/* Scrub a bnobt/cntbt record. */
STATIC int
xchk_allocbt_rec(
@@ -100,6 +124,7 @@ xchk_allocbt_rec(
const union xfs_btree_rec *rec)
{
struct xfs_alloc_rec_incore irec;
+ struct xchk_alloc *ca = bs->private;

xfs_alloc_btrec_to_irec(rec, &irec);
if (xfs_alloc_check_irec(bs->cur, &irec) != NULL) {
@@ -107,6 +132,7 @@ xchk_allocbt_rec(
return 0;
}

+ xchk_allocbt_mergeable(bs, ca, &irec);
xchk_allocbt_xref(bs->sc, &irec);

return 0;
@@ -118,10 +144,11 @@ xchk_allocbt(
struct xfs_scrub *sc,
xfs_btnum_t which)
{
+ struct xchk_alloc ca = { };
struct xfs_btree_cur *cur;

cur = which == XFS_BTNUM_BNO ? sc->sa.bno_cur : sc->sa.cnt_cur;
- return xchk_btree(sc, cur, xchk_allocbt_rec, &XFS_RMAP_OINFO_AG, NULL);
+ return xchk_btree(sc, cur, xchk_allocbt_rec, &XFS_RMAP_OINFO_AG, &ca);
}

int